The present invention relates to an adsorbent having an excellent adsorptivity, and more particularly to an adsorbent comprising built-up sheets utilizing activated carbon as an adsorbing agent.
Activated carbon has an excellent adsorption activity and has been used for various purposes, e.g. separation of gases, removal or recovery of solvents, and deodorization. Various adsorbents using activated carbon have hitherto been proposed.
For example, there is proposed an adsorbent having a honeycomb structure prepared by making a mixture of an activated carbon fiber, other fibrous materials and a heat-meltable binder into a paper, forming the paper into a honeycomb and building up the honeycombs (e.g. U.S. Pat. No. 4,259,092). However, since the adsorbent of this type contains the fibrous materials other than activated carbon in a high proportion, usually in a proportion of not less than 25% by weight and, therefore, the content of activated carbon is low, usually not more than 0.1 g/cm.sup.3, and since the heat-meltable binder stops up the pores of activated carbon to decrease the pores effective for adsorption, the adsorbent has the defect that the adsorptivity is low.
There is also known an adsorbent having a honeycomb structure prepared by making a paper having a high porosity which does not contain activated carbon, impregnating the paper with activated carbon and forming it into a honeycomb. However, this adsorbent also has the defect that the adsorptivity is low, since the proportion of fibrous materials other than activated carbon is high and the content of activated carbon is low.
It is an object of the present invention to provide an adsorbent having a high adsorption activity.
A further object of the present invention is to provide a sheet-like adsorbent having a high content of activated carbon and having a mechanical strength sufficient for use.
Another object of the present invention is to provide a process for preparing a shaped article which contains activated carbon in a high proportion with a high retention rate of the adsorption activity of the activated carbon used and is useful as an adsorbent.
These and other objects of the present invention will become apparent from the description hereinafter.